Electric bell



(No Model.)

W. J. MURDOOK.

ELECTRIC BELL.

No. 500,027. Patented June 20, 1893..

5 E 5 5 E N u w UNITED STATES PATENT ()FFICE.

VILLIAM J. MURDOOK, OF BOSTON, MASSACHUSETTS.

ELECTRIC BELL.

SPECIFICATION forming part of Letters Patent No. 500,027, dated June 20, 1893.

I Application filed March 18} 1898. Serial No. 466,575. (No model.)

To all whom it may concern:

Be it known that I, WILLIAMJ. MURDooK, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Magneto-Bells, of which the following isa specification.

Thisinvention relates to an improvement in magneto-bells of the kind employed as alarmbells, call-bells, and for like purposes where continuous ringing of the bell is desired.

The object of the invention is to provide an improved construction whereby slight vibrations of the armature will produce effective strokes of the bell-hammer.

The invention has further in view to simplify the construction of the bell, reduce the expense of manufacture, and render it more durable.

To these ends, the invention consists in certain novel features of construction and arrangements of parts, which will be fully described hereinafter and pointed out in the claims.

The accompanyin gd rawin gs illustrate a construction by which the invention may be carried out.

Figure 1 shows the actuating parts in elevation, with the bell proper removed. Fig. 2 shows a section taken on the line 22 of Fig. 1, and giving a plan view of the armature. Fig. 3 shows adetail perspective view of parts hereinafter referred to.

The same letters of reference indicate the same parts in all the figures.

In the drawings: The reference letter a designates a metal frame, which supports the electro-magnets b and 0. An armature cl is pivoted at one end on-a pin a, which is fasresilient material, is rigidly fastened on the upper or outer side of the armature, and a portion of said strip forms a tongue g,which projects from the end of the armature and is fastened rigidly on the flat side of the bellhammer boss. The strip g also forms a yielding tongue g which engages a contact-ten minal it, carried by a binding-post h to which a wire 1' from a suitable source of electricity is connected. Another wire 1', from the opposite pole of the battery or other source of electricity, is connected with a binding-post 2' and a third wire i connects said latter binding-post with the electro-magnets. The circuit is thus through the contact-terminal 72 tongue g armature (Z, frame a, the electro-magnets which are connected with said frame by a wire 7', the wire 2, and bindingpost 6 The tongue g tends to maintain the tongue d in contact with the terminal h and the armature separated from the magnet, and also to hold the bell-hammer away from the bell. WVhen the current is turned on through the bell, the electro-magnets act on the armature and draw the tongue g out of contact with the terminal 71, whereupon the circuit is broken and the tongue g returns to the tongue 9 into contact with said terminal. This action is substantially the same as in any ordinary magneto-bell, and will be readily understood. It will be observed that the armature and bell-hammer are'connected together at an angle to each other, and the tongue g and the bell-hammer form in effect a bell-crank lever. Said tongue being much shorter than the bellhammer, its slight vibrations, produced by the action of the magnets on the armature and its own resiliency,will resultin an effective stroke of the bell-hammer. By connecting the armature and bell-hammer at-an angle to each other, in the manner described, it will be seen that the parts may be assembled in smaller compass, and thus a more compact structure produced.

The bell proper n is fastened on a standard m, projecting from the frame a.

A magneto-bell constructed in accordance with my invention will possess the advantages of simplicity, durability and efficiency of operation.

The armature may be adjusted with relation to the magnets by means of a set-screw o, in the binding-post and having an insulated end which bears against an up-turned portion or arm g of the strip g. Said portion 9 is stiffer than the contact-tongue g and, by turning the set-screw o, the tendency of said tongue against the terminal h may be decreased so that the circuit may be more quickly broken. This adjustable feature will be found v of advantage in case of a weak current.

By reason of the compactness of the structure, all the parts are covered by and included within the circumference of the bell proper. The bell will be mounted in a suitable wood casing, comprising a base 19, to which the struction anelectroqnagnet, a pivoted armature having a resilient tongue, a pivoted bellhammer with which said tongue is connected, and means for completing a circuit through the armature and magnets, which circuit is maintained by the resilient tongue.

2. A magneto-bell, comprising in its construction, an electro-magnet, an armature pivoted at one end to a stationary support,a pivoted bell-hammer, a resilient strip connecting the armature and hammer at an angle to each other, and means for completing a circuit through the armature and magnets,which circuit is maintained by the resilient strip.

3. A magneto-bell, comprising in its construction an electromagnet, a pivoted armature, a pivoted bell-hammer, a contact't-erminal, and a strip of resilient material secured on the armature and forminga tongue which is connected with the bell-hammer and a tongue for contact with the said contact-terminal.

struction an electro-magnet, an armature pivoted at one end to a stationary support, a p1 voted bell-hammer, a resilient strip connecting the armature and hammer at an angle to each other, means for completing a circuit through the armature and magnets, which circuit is maintained by the resilient strip, and a bell covering and including within its circumference all the actuating mechanism.

5. A magneto-bell, comprising in its construction an electro-magnet, an armature pivoted at one end to a stationary support, a pivoted bell-ham mer, a resilient strip connecting the armature and hammerat an angle to each other, a resilient tongue on the armature and engaging a contact-terminal, a spring-arm on' I the armature, and an insulated set-screw engaging said arm.

In testimony whereof I have signed my nameto this specification, in the presence of two subscribing witnesses, this 15th day of March, A. D. 1893.

WILLIAM 'J. MURDOOK.

Witnesses:

O. F. BROWN, F. PARKER DAVIS.

. 4. A magneto-bell, comprising in its con- 

